TW201538973A - Flexible dissolved oxygen sensor - Google Patents

Abstract

A flexible dissolved oxygen sensor is disclosed, which is made by a semiconductor manufacturing process, including: a base layer made by a polymeric material and having flexibility; an electrode layer deposited on the base layer for sensing a potential signal; a solid electrolyte layer coated on the electrode layer for generating a potential signal according to oxygen; and an air permeable layer coated on the solid electrolyte layer for allowing oxygen in an external liquid to enter the solid electrolyte layer. Accordingly, the sensor can be attached to any submerged object by using a flexible substrate, a leakage problem can be solved by using a solid electrolyte, and an air permeable thin film can reduce damages caused by collision during measurement in a solution.

Description

Flexible dissolved oxygen sensor

The invention relates to a dissolved oxygen sensor for measuring the dissolved oxygen concentration in a solution, in particular to a flexible dissolved oxygen sensor, which mainly utilizes a flexible property and can be attached to any sinking On the water object, the amount of dissolved oxygen in the water is measured.

Generally, in the measurement of the electrochemical sensor, the three-electrode system consisting of the working electrode, the reference electrode and the dual electrode is mainly used, and the electrochemical potentiometer with the three-electrode system is used for the analysis and detection work. Among them, the working electrode material of the three electrodes is usually composed of gold, silver, platinum, etc.; the reference electrode is mainly silver/silver chloride electrode; the dual electrode is mainly gold or platinum electrode.

In the potential application, the working potential provided to the working electrode mainly corresponds to the reference electrode potential; the dual electrode is applied with the working potential; the reference electrode itself provides a constant potential, which does not increase or decrease with the reaction current. The potential change is different from the electrochemical sensing system of the two electrodes. The advantage of the three-electrode system is that the addition of the reference electrode not only effectively compensates for the potential drop generated by the internal resistance, so the applied working potential does not shift and float. Move, so that the accuracy of detection is greatly improved.

At present, the commercially available commercial dissolved oxygen meter is mainly measured by a two-electrode type and a constant potential amperage method, and the design part of the sensor directly measures the oxygen reduction signal by an inert electrode, and cooperates with The highly specific oxygen permeable membrane covering the front end of the electrode only allows oxygen dissolved in the liquid to enter and exit the surface of the membrane, thus effectively blocking the entry of other interfering substances. However, such a device must be placed in a flowing or agitated system to accurately measure the dissolved oxygen value. In addition, the sensor casing and the film are easily damaged by collision, and the internal electrolyte solution is prone to leakage and must be regularly maintained. And replacement, adding a lot of operational inconvenience.

In addition, since the traditional detection of oxygen in water requires the addition of a liquid electrolyte between the electrode and the gas permeable membrane, the liquid electrolyte has a liquid leakage problem after prolonged use. Therefore, some methods for improving leakage have been gradually researched and published. In the prior art, such as Wends Glasspool and John Atkinson, Sensors and Actuators B (Wendy Glasspool, John Atkinson, Sensors and Actuators B, 1998, 48, 308), mainly using gold, silver/silver chloride as sensing electrodes, The electrode material of the counter electrode and the reference electrode is coated with a potassium nitrate gel (KNO ₃ ) as an electrolyte, and in addition to potassium nitrate, both Nafion and yttrium zirconia (YSZ) can also be used. Used to detect oxygen concentration.

In the conventional art, for example, the Republic of China Patent No. M274531 discloses a dissolved oxygen sensing device comprising a tubular body having an opening at both ends, the opening of one end of which is provided with a cap to close the opening, and the other end is assembled to be detachable. Dissolve The oxygen permeable membrane is internally provided with an electrode support seat for dividing the internal space of the tubular body into two parts, and the silicone support and the electrolyte are respectively filled between the electrode support seat and the tube cap and the dissolved oxygen permeable membrane, and the voltage recording is arranged outside the body The voltage recorder is respectively provided with a cathode and an anode reaction metal extending through the cap to the electrolyte, and a thermocouple wire extending to the silicone, and a resistor is connected between the cathode and the anode reaction metal.

In the prior art, the dissolved oxygen sensing device is a two-electrode type and the volume is not easy to be miniaturized, and has no flexible characteristics, and cannot be attached to any submerged object. In addition, the liquid electrolyte is prone to leakage. .

The object of the present invention is to provide a flexible dissolved oxygen sensor, which is mainly a sensor formed by a semiconductor process, which is formed by replacing a conventional hard outer casing with a polymer film to form a flexible substrate, and utilizes The solid electrolyte replaces the liquid electrolyte currently used, and is directly attached to the solid electrolyte by the gas permeable membrane, whereby the flexible substrate can be used to attach the sensor to any submerged object, and the solid electrolyte can be used to solve the liquid leakage problem. The use of a gas permeable film can reduce damage caused by collisions when measured in a solution.

The invention discloses a flexible dissolved oxygen sensor which is formed by a semiconductor process, comprising: a base layer which is a polymer material and has flexibility; and an electrode layer deposited on the base layer for sensing potential a solid electrolyte layer coated on the electrode layer to generate a potential signal according to oxygen; and a gas permeable layer coated on the solid electrolyte layer for allowing oxygen in the external liquid to enter the solid state Electrolyte layer.

As mentioned above, in one embodiment, the substrate layer is made of parylene.

As described above, in an embodiment, the electrode layer includes a gold electrode region, a silver electrode region, and a reference electrode region, and the gold electrode region, the silver electrode region, and the reference electrode region are respectively separated by a parylene region, wherein the reference electrode The region includes a reference electrode and the reference electrode is silver chloride.

As described above, in one embodiment, the gold electrode region, the silver electrode region, and the reference electrode region and the substrate layer include an adhesion layer, and the adhesion layer is made of chromium.

As described above, in an embodiment, the material of the solid electrolyte layer includes a component of potassium chloride.

As described above, in one embodiment, the material of the gas permeable layer is cellulose acetate, ruthenium rubber or polystyrene.

The invention forms a flexible substrate by using a parylene film, so that the flexible dissolved oxygen sensor can be attached to any submerged object, and then the solid formed by mixing the gelatin powder with potassium chloride The electrolyte replaces the liquid electrolyte currently used to solve the liquid leakage problem. Finally, the gas permeable membrane formed by mixing the ethylene glycol diethyl ether with the cellulose acetate directly adheres to the solid electrolyte can reduce the damage caused by the collision in the measurement in the solution.

10‧‧‧矽 substrate

11‧‧‧ basal layer

12‧‧‧Adhesive layer

15‧‧‧electrode layer

20‧‧ gold

21‧‧‧Gold Electrode Zone

30‧‧‧Polypylene

35‧‧‧Positive photoresist

40‧‧‧Silver

41‧‧‧Silver electrode area

50‧‧‧ reference electrode

51‧‧‧ reference electrode area

60‧‧‧Solid electrolyte

70‧‧‧ breathable layer

1 is a method of manufacturing a flexible dissolved oxygen sensor according to the present invention A cross-sectional view of the accumulation of p-xylene, chromium and gold.

2 is a cross-sectional view of an etched gold in a method of manufacturing a flexible dissolved oxygen sensor in accordance with the present invention.

3 is a cross-sectional view showing etching of chromium in a method of manufacturing a flexible dissolved oxygen sensor according to the present invention.

Figure 4 is a cross-sectional view showing the deposition of parylene in a method of manufacturing a flexible dissolved oxygen sensor in accordance with the present invention.

Figure 5 is a cross-sectional view showing the removal of parylene in a method of manufacturing a flexible dissolved oxygen sensor in accordance with the present invention.

Figure 6 is a cross-sectional view showing the deposition of silver in a method of manufacturing a flexible dissolved oxygen sensor in accordance with the present invention.

Figure 7 is a cross-sectional view showing the removal of photoresist in a method of manufacturing a flexible dissolved oxygen sensor in accordance with the present invention.

Figure 8 is a cross-sectional view showing the formation of silver chloride in a method of manufacturing a flexible dissolved oxygen sensor according to the present invention.

Figure 9 is a cross-sectional view showing the formation of a solid electrolyte layer in a method of manufacturing a flexible dissolved oxygen sensor according to the present invention.

Figure 10 is a cross-sectional view showing the formation of a gas permeable layer in a method of manufacturing a flexible dissolved oxygen sensor according to the present invention.

Figure 11 is a cross-sectional view showing the removal of a tantalum substrate in a method of manufacturing a flexible dissolved oxygen sensor according to the present invention.

In order to make the above and other objects, features, and advantages of the present invention more apparent, the following detailed description will be made in conjunction with the accompanying drawings. The invention discloses a flexible dissolved oxygen sensor, and the manufacturing method thereof comprises: first, Please refer to FIG. 1. FIG. 1 is a cross-sectional view showing deposition of parylene, chromium and gold in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention. The tantalum substrate 10 is first provided, then the base layer 11 is deposited on the tantalum substrate 10, then the adhesion layer 12 is deposited on the base layer 11, and then gold 20 (Au) is deposited on the adhesion layer 12.

As described above, in one embodiment, the base layer 11 is parylene, the adhesion layer 12 is chromium (Cr), and the deposition adhesion layer 12 is chromium for the purpose of increasing the adhesion of the gold 20.

Next, please refer to FIG. 2. FIG. 2 is a cross-sectional view showing etching gold in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention. The positive photoresist is uniformly applied to the gold 20 by a spin coater, and then exposed and developed using a photomask. At this time, the photoresist blocked by the mask is not exposed, so it remains on the gold 20, and then the germanium substrate 10 is placed. In the gold etching solution, the photoresist on the surface of the germanium substrate 10 can be used as a protective layer for gold etching. After etching, the photoresist on the surface of the germanium substrate 10 is removed by acetone, that is, gold etching is completed.

Next, please refer to FIG. 3. FIG. 3 is a cross-sectional view showing etching of chromium in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention. The positive photoresist is uniformly coated on the substrate 10 which has been subjected to gold etching by a spin coater, and then exposed and developed using a photomask, and the gold 20 on the substrate 10 is protected by the photoresist, and then The crucible substrate 10 is placed in a chromium etching solution for chromium etching, and then the photoresist is removed using acetone to complete the chromium etching.

Next, please refer to FIG. 4. FIG. 4 is a cross-sectional view showing deposition of parylene in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention. After the steps of the gold etching and the chromium etching are completed, the parylene 30 is deposited on the surface of the germanium substrate 10 in order to prevent the short circuit from being caused when the wire is measured in water.

Next, please refer to FIG. 5. FIG. 5 is a cross-sectional view showing the removal of parylene in the manufacturing method of the flexible dissolved oxygen sensor according to the present invention. Then, the photoresist is uniformly coated on the surface of the ruthenium substrate 10 by a spin coater, and then exposed and developed to complete the opening above the gold 20 in the electrode pattern on the surface of the ruthenium substrate 10 and define the shape of the sensor. The parylene 30 above and below the gold 20 is removed by a reactive ion etching machine, and finally the photoresist is removed by acetone, that is, the gold electrode region 21 in the three electrodes is completed.

Next, please refer to FIG. 6 and FIG. 7. FIG. 6 is a cross-sectional view showing deposition of silver in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention, and FIG. 7 is a flexible oxygen sensing sensor according to the present invention. A cross-sectional view of the photoresist removed in the manufacturing method. The above steps are repeated, and the positive photoresist 35 is uniformly coated on the gold electrode region 21 and the surface of the parylene 30 by a spin coater, and then exposed and developed to deposit on the surface of the ruthenium substrate 10. After the silver electrode is opened, and then the silver 40 is deposited, the photoresist is removed by the Lift-off technique, and the silver 40 in the opening is left, which is the completion of the silver electrode region 41.

Next, please refer to FIG. 8, which is a flexible method according to the present invention. A cross-sectional view of the formation of silver chloride in the method of manufacturing a dissolved oxygen sensor. The above steps are repeated, and the positive photoresist is uniformly applied to the completed gold electrode region 21 and the silver electrode region 41 by a spin coater, and then exposed and developed, and the opening is completed above the silver 40 in the electrode pattern on the substrate 10 Then, the ruthenium substrate 10 is placed in silver chloride to form a reference electrode 50, and finally the photoresist is removed by acetone, that is, the reference electrode region 51 is completed.

Next, please refer to FIG. 9. FIG. 9 is a cross-sectional view showing the formation of a solid electrolyte layer in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention. Next, a solid electrolyte 60 containing a potassium chloride component and a gel powder is applied over the gold electrode region 21, the silver electrode region 41, and the reference electrode region 51, and after solidification to be cooled, the coating of the solid electrolyte 60 is completed.

Next, please refer to FIG. 10. FIG. 10 is a cross-sectional view showing the formation of a gas permeable layer in a method for manufacturing a flexible dissolved oxygen sensor according to the present invention. Next, a gas permeable layer 70 of cellulose acetate, ruthenium rubber or polystyrene is applied over the solid electrolyte 60, and after the solidification is cooled, the coating of the gas permeable layer 70 is completed.

Finally, please refer to FIG. 11. FIG. 11 is a cross-sectional view showing the removal of the germanium substrate in the manufacturing method of the flexible dissolved oxygen sensor according to the present invention. Then, the base layer 11 is separated from the ruthenium substrate 10 by the detachment method, that is, the fabrication of the flexible dissolved oxygen sensor is completed.

The present invention is formed by the method of the above semiconductor process to form a flexible dissolved oxygen sensor, comprising: a base layer 11 which is a polymer material and has flexibility; and an electrode layer 15 deposited on the base layer 11 for Sense potential signal; The solid electrolyte layer 60 is coated on the electrode layer 15 to generate a potential signal according to oxygen; and the gas permeable layer 70 is coated on the solid electrolyte layer 60 for allowing oxygen in the external liquid to enter the solid electrolyte layer 60.

As described above, since the pores of the gas permeable layer 70 are small, oxygen in the liquid can be passed, and then the potential signal is generated according to the amount of oxygen permeated through the solid electrolyte 60, and then the electrode layer 15 senses the potential signal to generate dissolved oxygen corresponding to the amount of oxygen. The sensed value is used to measure the oxygen content in the liquid.

As described above, in an embodiment, the base layer 11 is made of parylene.

As described above, in an embodiment, the electrode layer 15 includes the gold electrode 21 region, the silver electrode region 41, and the reference electrode region 51, and the gold electrode region 21, the silver electrode region 41, and the reference electrode region 51 are respectively composed of parylene 30. The regions are spaced apart, wherein the reference electrode region 51 includes a reference electrode 50 and the reference electrode 50 is silver chloride.

As described above, in an embodiment, the gold electrode region 21, the silver electrode region 41, and the reference electrode region 51 and the base layer 11 further include an adhesion layer 12 made of chrome.

As described above, in an embodiment, the material of the solid electrolyte layer 60 includes a component of potassium chloride.

As described above, in one embodiment, the material of the gas permeable layer 70 is cellulose acetate, ruthenium rubber or polystyrene.

The invention forms a flexible substrate by using a parylene film, so that the sensor can be attached to any submerged object, and then by chlorination The solid electrolyte of potassium replaces the liquid electrolyte currently used to solve the liquid leakage problem. Finally, the gas-permeable film formed by cellulose acetate, ruthenium rubber or polystyrene is directly attached to the solid electrolyte to reduce the measurement in the solution. Damage due to collision.

The flexible oxygen absorbing sensor of the present invention is mainly manufactured by using a semiconductor process, thereby facilitating miniaturization of the package. In addition, by spin coating the conductive gel on the electrode, in addition to its own activity, it can also increase the firmness of the electrode on the gas permeable layer, thereby improving the stability of the induced current, especially the gold electrode used in the present invention. There is quite good oxygen sensing properties.

In summary, it is merely described that the present invention is an implementation or embodiment of the technical means employed to solve the problem, and is not intended to limit the scope of implementation of the present patent. Any change or modification that is consistent with the scope of the patent application scope of this creation or the scope of the patent creation is covered by the scope of the creation patent.

11‧‧‧ basal layer

15‧‧‧electrode layer

20‧‧ gold

21‧‧‧Gold Electrode Zone

30‧‧‧Polypylene

40‧‧‧Silver

41‧‧‧Silver electrode area

50‧‧‧ reference electrode

51‧‧‧ reference electrode area

60‧‧‧Solid electrolyte

70‧‧‧ breathable layer

Claims (8)

A flexible dissolved oxygen sensor is formed by a semiconductor process, comprising: a base layer which is a polymer material and has flexibility; an electrode layer deposited on the base layer for sensing a potential signal; a solid electrolyte layer coated on the electrode layer to generate the potential signal according to an oxygen gas; and a gas permeable layer coated on the solid electrolyte layer for allowing the oxygen in the external liquid to enter the Solid electrolyte layer. A flexible oxygen absorbing sensor according to claim 1, wherein the substrate layer is made of parylene. The flexible oxygen-dissolving sensor of claim 1, wherein the electrode layer comprises a gold electrode region, a silver electrode region and a reference electrode region, and the gold electrode region, the silver electrode region and the reference The electrode regions are separated by a parylene zone, respectively. A flexible oxygen absorbing sensor according to claim 3, wherein the reference electrode region comprises a reference electrode, and the reference electrode is silver chloride. The flexible oxygen absorbing sensor of claim 3, wherein the gold electrode region, the silver electrode region, and the reference electrode region and the substrate layer comprise an adhesion layer. A flexible oxygen absorbing sensor according to claim 5, wherein the adhesive layer is made of chrome. A flexible oxygen absorbing sensor according to claim 1, wherein the material of the solid electrolyte layer comprises potassium chloride. The flexible oxygen absorbing sensor of claim 1, wherein the gas permeable layer is made of cellulose acetate, ruthenium rubber or polystyrene.